Due to advancement of technologies, use of mobile communication apparatuses such as mobile phones, personal digital assistants (PDAs) and tablet computers (e.g., iPads) is increasingly widespread. Because their functions become increasingly diversified, power consumption of such mobile communication apparatuses also increases continuously. Meanwhile, as such mobile communication apparatuses are used more and more frequently, energy consumed is also increasing, and it is often the case that several backup batteries must be used every day or the battery must be recharged frequently. Furthermore, if a user staying in an environment where no recharging power source is available (e.g. a suburban area) does not carry a backup battery with him/her, then his/her mobile communication apparatus may run out of power and fail to operate any longer, which may present unnecessary troubles for the user. Also, in some emergencies, if the mobile communication apparatus runs out of power and cannot be recharged in time, unnecessary losses might be caused or the user might be put at risk.